What’s Vulnerable › Vulnerabilities
CVE-2025-31137: Remix and React Router allow URL manipulation via Host / X-Forwarded-Host headers
- Severity: high (CVSS 7.5 v3.0)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 1.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2025-04-01 · updated 2026-06-17
- Weakness: CWE-444
Description
React Router is a multi-strategy router for React bridging the gap from React 18 to React 19. There is a vulnerability in Remix/React Router that affects all Remix 2 and React Router 7 consumers using the Express adapter. Basically, this vulnerability allows anyone to spoof the URL used in an incoming Request by putting a URL pathname in the port section of a URL that is part of a Host or X-Forwarded-Host header sent to a Remix/React Router request handler. This issue has been patched and released in Remix 2.16.3 and React Router 7.4.1.
Affected products
- remix-run react-router: from 7.0.0, < 7.4.1; from 2.11.1, < 2.16.3
References
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